This invention relates to a new composition for washing and conditioning hair and, more particularly, to a new composition providing both a shampooing and a conditioning action in a single application.
Human hair becomes soiled due to sebum secreted naturally by the scalp as well as soil and other atmospheric contaminants which accumulate on the hair. The build-up of sebum causes the hair to have a greasy, dirty feel, poor manageability, and an unattractive appearance. Shampooing the hair cleans by removing from the hair excess oil, sebum, atmospheric contaminants, and the residues due to the usage of a variety of hair styling products, such as sprays, gels and mousses. The most effective shampoos are those that contain high lather synthetic anionic surfactants, such as the long chain alkyl sulfates and the long chain alkyl ether sulfates. These shampoos are very effective for cleansing the hair but, after rinsing with water, they leave the hair in an unmanageable state. Thoroughly cleansed hair is extremely difficult to comb in both wet and dry states because the individual hair fibers tend to tangle with each other. Also, thoroughly cleansed hair in the dry state has undesirable electrostatic properties in a relatively low humidity atmosphere which cause the hair to "fly away," thereby further reducing the overall manageability of the hair.
A variety of means have been developed to alleviate the problems associated with after-shampooed hair. These range from using after-shampoo hair conditioner to including hair conditioning agents directly to the shampoo compositions. After-shampoo hair conditioners are easily formulated but must be applied in a separate step following the shampooing. This, of course, is time-consuming and inconvenient. Among the most effective hair conditioners are those that contain cationic surfactants such as long chain dialkyl dimonium chlorides.
The formulation of shampoo with conditioning agents has been difficult due to several reasons. One problem relates to the usual incompatibility between anionic surfactants and cationic surfactants. The combination of anionic surfactants with cationic surfactants often reduces the respective cleansing and conditioning effectiveness of each surfactant. This is because combining a cationic surfactant with an anionic surfactant causes the formation of a water insoluble species. A partial solution to this incompatibility problem in formulating conditioning shampoos is to examine other surfactants such as nonionics and amphoterics for use as conditioning agents in place of cationics. Unfortunately, the use of these other surfactants has not solved all the problems associated with formulating conditioning shampoos.
Another problem associated with formulating a conditioning shampoo is the instability that results when water-insoluble conditioning agents are included in the composition, such as the non-volatile silicones which have a good conditioning property that provides a degree of softness and luster to the hair. A particularly difficult problem to solve with silicone-containing conditioning shampoos is that of keeping a dispersed, water-insoluble, non-volatile silicone material suspended in stable form while retaining the desirable performance of the conditioning shampoos. The following references represent efforts by industry to solve this problem: U.S. Pat. No. 5,034,218 to Duvel, U.S. Pat. No. 4,704,272 to Oh et al.; and U.S. Pat. No. 4,902,499 to Bolish, Jr. et al. Despite these efforts, there is a continuing need for the discovery of improved stable conditioning shampoos which have compatible anionic surfactants and cationic conditioning surfactants, thoroughly cleanse the hair, and impart improved physical and cosmetic properties to hair such as wet and dry comb, wet and dry feel, gloss, static control and manageability, yet do not cause build-up on human hair as is common with many conditioning shampoos.